Drying oven



R. R. LUNDY DRYING OVEN Aug. 4, 1936.

F'iled Jan. l2, 1934 4 Sheets-Sheet 2 3mm/M100 Woher? R andy plun www IlI NNN.. Nm zockmz.

Aug. 4, 1936. R. R. LUNDY DRYING OVEN med Jan. 12, 1954 l 4 Sheets-Sheet5 Rober! l?. LundyV mwlzflw (MWTMMW Aug. 4, 1936.

R.R.LUNDY DRYING OVEN Filed Jan. 12, 1934 4 Sheets-Sheet 4 Patented Aug.4, 1936 unirsi) srAT'ss PATENT @F-FCE atacan Darme oven Robert R. Lundy,South Bend, Ind.

Application January 12, 193i, serial No. 706,348

s claims. (ci. :i4- 19) This invention relates to improvements in dryingovens and particularly to drying ovens for performing a siccative actionon objects of relativel`y`large size, and has for its principal objectthe provision of drying or baking ovens for performing a siccativeaction on single objects, or small groups of objects, individually.

A further object resides in the provision of drying or baking ovenswhich may be applied to one or more of a train of articles ofmanufacture moving on a continuous track, without affecting thesiccative action on other articles in the train or interrupting theprogress oi' the train.

A still further object of the invention lies in the provision of adrying or baking oven which completely encloses the article to betreated, in either a stationary or moving lposition-and prevents orretards the escape of heated, or otherwise treated, air or gas, from theoven during the siccative action, thus reducing the cost of theoperation and preventing the deposit of dust or foreign matter on thewet surface of the object.

An additional object o! lthis invention resides in the provision of adrying or baking oven wherel by a siccative action may be obtained at alow operating cost vbecause of simplicity of article processing and ovenhandling equipment. Another object resides in the provision of a ,Ndrying or baking oven which completely encloses the article to betreated, in either a stationary or moving position, thereby maintaininga uniform temperature inthe enclosurejregardless of air conditionsoutside of the oven. v

Other objects and advantages oi' the invention will appear as thedescription proceeds. In the accompanying drawings I have illustratedone mechanical embodiment of the ideaof the invention and severalslightly modiied forms, together with suitable methods of operationthereot. The drawings, however, are for the purpose of illustration onlyand are not to be considered as limiting the invention, the scope o!vwhich is to be .measured entirely bythe scope of the. subjoined claims.

In the drawings: v

Figs. 1a and 1b illustrate the application of my improved drying oven toa production line carrying objects such as automobile bodies;`

Fig. 2 is a vertical elevational view of on form of my improved dryingoven;

Fig, 3 is a transverse sectional view taken on the line 3-3 of Fig. 2:

4 is afragmentary view similar toFig. 2

modiiled form of drying oven showing a movable l the time speciiled, thenumber of trucks ordinarily showing a somewhat modiiled form of thedevice of the invention;

Fig. 5 illustrates a somewhat diierent application of my improved dryingoven to a production line carrying objects such 'as automobile 5bodies,- from the application illustrated in Fig. l;

Fig. 6 is an end elevational view of a modified form of my improveddrying oven and means for supporting the same;

Fig. 7 is a side elevational view of the drying 10l oven illustrated inFig. 6.

Fig. 8 is a sectional view of a plant building showing a diierentapplication of my improved drying oven from that illustrated in Figs.1a. and lb and 5; l5

Fig. 9 is an elevational view ofv a drying oven especially adapted forthe application illustrated in Fig. 8;'and

Fig. 10 is a fragmentary elevational view of a hinged end or sidetherefor.

Referring to the drawings in detail, and particularly to Figs. la and1b, the numeral i0 designates a continuous tracklaid on the floor li andupon which a series of trucks I2, supported thereon by suitable wheelsor rollers I4 is adapted to travel.

Carried upon each truck is an article oil-manufacture such as anautomobile body I5. In the application of the device as illustrated, thearticle i5 receives a coating s'uch as paint or lacquer in the spraybooth Il and emerges from the booth with the coating in a we or solventcondition. This wet coating mustreceive siccative action' before thearticle can be handled and the next step oi' the manufacturingprocess-begun.

In order to accomplish the siccative action of these wet coated articlesin the least possible time and at the minimum expense I have provided aplurality of special drying ovens 2li. The n umber of ovens required tocarry out the method of my invention depends upon, and is largelydetermined by, three factors, namely, the length of time required forthe siccative action, the speed with which the trucks carrying thecoated articles -pass over the track, .and the number of trucks upon agiven length of track. Having/Vl ilrst determined the maximum timerequired for the siccative action of the coating of the type underconsideration, a length of track is laid oil', as illustrated in Figs.1a and 1b', such that a truck carrying a coated article will pass fromone end to the other, of the measured length of track in supported uponthis length of track is then determined. To this number must be addedenough reserve ovens to render the process continuous in placing theovens over the articles and removing them therefrom in addition to asmall number of spare ovens for use in case one or more of the ovensshould develop mechanical troubles which would necessitate its temporaryremoval from service.

As further illustrated in Figs. la and lb, the

length of track specified above is provided with 1 an overhead trolley22 embodying three electrical conductors 22a, 22h, and 22e carried bysuitable supports 23 of insulating material. While I have illustratedand described an overhead, three-bar trolley, it is to be understoodthat the invention is in no way limited to this type of electricalconductor and that any other suitable type, such as a third-rail" type,may be used if desired.

At a distance above the above mentioned length of track, somewhatgreater than twice the height of each of the drying ovens 20, I haveprovided a suspension track 24 secured to the ceiling 25 by suitablesupports 23. This suspension track 24 has a generally rectangular crosssection andis provided with a slot extending continuously along theunder side thereof. At each end of the suspension track, I have provideda hoisting mechanism generally indicated at 21 and 29. Each hoistingmechanism comprises a pair of flexible cables 3i land 32 each connectedat one end thereof to a member 34 which is similar in all respects to ashort section of the suspension track 24. The cables 3| and 32 arecarried over pulleys 33 and 31 respectively secured to the ceiling 23and are engaged at their ends opposite the member u with the Vdrum or ahoisting windlass 33.- r

From the illustration andthe above description, it will be observed thatwhen either member 34 is carried to its uppermost position it forms, inefl'ect, a continuous part of the suspension track 24. It will befurther observed that the hoisting-mechanism 21 is so located as to beadapted to place one of the ovens 20 over the article I3 as the articleemerges from the spray booth I3 and that the hoisting mechanism 23, isso located as'to remove the oven from the article at vthe end of thesuspension track 24.

In Fig. 1a I have illustrated a platform 42 located abovethetrack l0 andsupported from the ceiling or from the floor at such a height as topermit the ovens carried by the ysuspension track 24 to pass over it. insuch positionthat `tion in Fig. 1a that this platform 42 terminates at asufiicient distance from the booth I3 to permit ovens to be loweredbetween the booth and the, end of the platform and, that the platformextends a sufficient distance alongthe track to cover the open bottomsof two or more ovens at the same time. At this time it should also beunderstood that the trucks l2 are provided with solid or continuousplatforms 44 which eectively close the open bottoms of the ovens 20 whenthe ovens are in operative position upon the trucks. A short trolley 43is provided above the platform 42 so that the heating elements of theoven may be energized to preneet the ovens while they rest upon theplatform 42.

baking oven illustrated therein comprises, in general, an elongated,substantially rectangular, boxlike structure having five complete wallsand an open bottom. Preferably, the oven is composed of an innerstructure 45 of sheet metal uniformly spaced from a similar outerstructure 4 6 of the same material with suitable insulating material 41,such as asbestos fiber, compressed between the inner and outerstructures. Suitable joints and bracing, such as the gusset plate 48,may be used to render the ovenrigid and durable. It is to be understood,however, that an oven comprising a single structure of sheet metal orother suitable material is within the scope of the invention.

The size and shape of my improved drying oven may also be altered toaccommodate the oven to the size and shape oi' various articles ofmanufacture without in any way departing from the scope oi' theinvention. Also, while I have illustrated an oven adapted to enclose asingle relatively large article, such as an automobile body, it is to beunderstood that a group of two or more smaller articles, such as easingsfor electric refrigerators, may be enclosed within one oven at the sametime.

Referring particularly to Fig. 2, it will be observed that I haveprovided on the upper portion of my improved oven a pair of liftingdevices 50 and 50'. Each of these lifting devices comprises a stem 5|secured at its lower end to the top of the oven and provided with a thinportion adapted to travel through the slot in the bottom portion of thesuspension rail 24. At its upper end each stem 5| carries a transversepin 52 upon the opposite end portions of which is mounted a pair oi'rollers 33 in end to end relation adapted to travel upon the bottomportionI of the suspension rail 24, one upon each side of the slot.Referring to Figs. la and 1b.` it will be observed that these liftingdevices 50 and 50 are utilized in combination with the members 34 tolower the oven over the article and raise it fromthe article by theengagement of thel lifting devices with the members 34 as well as tosupport the oven on the suspension rail 24 during the return of the ovenfrom the end to the beginning of the drying section of the track I0.

Each of my improved ovens is also provided with an individual heatingdevice such as the electrical resistance heater indicated at I3 in Figs.la and 2. If desired. these heaters may be separately controlled as bythe rheostat 31 and the internal temperature ofeach oven may bedisplayed by a temperature indicating device such as the thermometer 30during the entire siccative action. It is also within the scope of theinvention to apply automatic control devices to theA heating elements ofthese portable ovens to automatically maintain a predeterminedtemperature or series of temperatures during the siccative action. y

. The numeral 32 indicates an electric fan which -I have illustrated aslet into one end of the oven and which isr operative to circulate theair or other gas contained within the oven, about the article which isbeing dried, or may force air from outside the oven into the oven ifdesired.

While, for the sake of clearness in the draw` ings, I have shown theoven heating device l5 located at a distance from the fan 42, it is tobe understood that the heating element may be, and preferably is,combined with the fan, if a fan is Referring now to Figs. 2 and 3, itwill be obused served that the form oi my improved drying lor rn'rig. 21 have also muetreted a vent s rm- 75 erwise than by heating it. If afan is used, the

air humidifier or drier or filter 'l0 is preferably disposed between thefan 62 and the heating element 55 but may be located in any part of theoven without departing from the scope of the invention.

Referring back to Fig. 2, it will be observed that I haveprovided'suitable electrical connections and conductors for connectingthe trolley 22 with the various electrically operated devices includedin my improved oven. The numeral 12 generally indicates a trolley harpcomprising a handle or supporting portion 13 and a contact carryingblock 14. The contacts, not illustrated, carried by the block it areconnected to exible conductors 15 which are led through the upperportion of the oven and secured thereto by means of suitable insulatorsTl. From the insulators il the co uctors are led to the rheostat, theheating eement, the fan, and any other electrically operated devicecontained within the oven.

It will be noted that the exible portions of the conductors l5, betweenthe block 14 and the insulators il, are of suiiicient length to permit aconsiderable latitude of movement to the trolley harp 12. The trolleyharp handle 73 is detachably secured to the oven to hold the contactblock in contact with the trolley 22 by means of a bracket 00 secured toa side of the oven. Referring to Figure la it will be observed that theharp 'i2 is disconnected from the trolley 22 at the time the oven isfirst lowered over the wet coated article but may be connected as theoven moves along with the truck I2 by manually inserting the handle i3in the bracket 00.

In Figs. 5, 6, and 7, I have illustrated a somewhat modifled form ofdrying oven and a diderent manner of handling the same from thatiilustrated in Figs. 1a, lb, 2, and 3. In this modi- 'ed form of theinvention, instead of having trucks which run upon tracks mounted on thefloor, I utilize platforms carried upon roller conveyers located at eachend of the drying line, suspension tracks for supporting the ovens, andplatforms during the drying or siccative process and returning the ovensfrom the end to the beginning of :the drying line, a chain conveyor' forpropelling the ovens and platforms along the drying line, andinterlocking elements acarried by the ovens and platforms to latch theplatforms to the ovens during the siccative process.

In Fig. 5, I have illustrated an alternative manner of handling theovens from that illustrated in Figs. la and lb. In this alternativemanner, the objects of manufacture such as the automobile bodies asindicated at i5 are carried upon iiat platforms-00 and emerge from thespray booth (not illustrated in this figure) upon a roller conveyor |00mounted on the i'ioor at the beginning of the drying line. At the end ofthe drying line is a similar roller conveyor |0| and between the tworoller conveyors is a chain conveyor |03. overlying the chain conveyorand extending somewhat beyond each end thereof are a pair of suspensiontracks |05 and |06 of I-section shown in end view'in Fig.'6. Thesetracks may be supported from the floor orvthelceiling by suitable .meanssuch as the vertical hangersj Immediately above the suspension tracks,V

|05 and |06 at a vertical distance thereabove somewhat greater than theheight of the drying ovens yis a second pair of suspension tracksindicated at |24 also secured to the ceiling as by hangers 09. A tracksis a hoisting device generally indicated at |21 and |20. Each hoistingvmechanism comprises two pair of flexible cables as indicated at |3| and|32, each cable/of each pair being connectedat one end thereof to amember |34, thesey members being similar in all respects to a short`section of the suspension tracks. The` cables are carried over pulleysas indicated at |36 and |31 secured to the ceiling |25 and are engagedat their ends opposite the members |34 with the 4drums of the hoistingwindlasses as indicated at From this description, it will be observedthat the members |34 may be moved by means of the hoisting mechanismsfrom one to the other of two operative positions in which theyconstitute a continuation of the track |06 or the track |24 and that bymeans of these members and the associated hoisting mechanisms the ovensmay be shifted from the upper to the lower suspension tracks at thebeginning of the drying process and from the lower to the upper track atthe end of the drying process. During the drying process, the ovens aremovedalong the lower track by the chain conveyor |03 and at the end ofthe process the ovens may bereturned manually or other- Y/wise valongthe upper track |24.

The hoisting mechanisms overlie the respective roller conveyors |00 and|0| so that the platforms 94 are picked up from and set down on therollers at the beginning and the end of the drying process. Theplatforms are not returned with the ovens but carry the' articles on tothe end of the production line, of which the drying or siccative processconstitutes a part, and are re turned to the head of the .productionline.

In combination with the above described method ofhandling the ovens, Ihave provided a somewhat modied form of oven |00 particularlyillustrated in Figs. 6 and 7. It is to be understood, however, that thediierent ovens illustrated and described are completely7 interchangeableand may be adaptedv to the different methods of handling by simplyinstalling the proper carrying and current supplying devices.

The oven |00 illustrated in Figs. 5 and 6 preferably comprises an innerand outer wall structure with insulating material betweenthe two wallsas illustrated in Fig. 3. In addition to the construction illustrated inFigs. 2 and 3, the oven |00 is provided with side walls ili which slopeoutwardly from. top to bottom to provide a space between the lower edgeof each side wall and the adjacent edge of the platform 9d. These spacesmay be closed bymovable closure members |02 .secured to the end walls ofthe hood by pivoted links idd and |55.

I have provided'indentations |50 in the upper portion of the oven |00 ateach end thereof and in one of these indentations I have mounted an airconditioning device generally indicated at |52 comprising an air heaterand drier |55, a fan |52,

and a motor |63 for operating the fan. I have also provided ducts |54for conveying the heated At each end of the suspension air from theheater |55 to the central portion of the oven. A vent |65 is provided inthe upper portion of each oven to permit the escape of air therefrom.

For\purposes of carrying the empty oven or the oven and platform andarticle during the siccative action, I have provided carriers |10secured to the oven on the upper portion of the sides thereof andcontaining rollers |12 which run upon the tracks |06 or |24, there beingtwo such carriers on each side of each oven.

In order that electric current may be supplied to the oven during thesiccative action or the preheating period, I have provided a sidebracket adapted to support a handle |13 provided at its upper end with ablock or trolley |14 adapted to contact an electrical conductor |22.

Referring to Fig. 6 it will be observed that 'each of the platforms 84is provided at its ends with hooks |84 and that each of the ovens |40 isprovided at each of its ends with a substantially U- shaped bar |85pivotally secured to the oven by brackets |86 and terminating inbent-over ends |81 adapted to engage the hooks |84 to releasably securethe ovens |40 to the platforms 84 so that the oven, platform and articlemay be picked up as a unit by the hoisting mechanism and moved as a unitalong the lower suspension track during the siccative action.

The method of operation of the device is substant'ially as follows: aseach wet coated article emerges from the spray booth |8 an oven is low-'ered over the article and permitted to rest upon the platform carryingthe article thus together with the platform, forming a ltight enclosingspace only slightly larger than the article. The trolley harp is thenconnected to the trolley by inserting the handle in the bracket. Theheating element and fan are thereby energized and the siccative actionproceeds for the specifled length of time. At the end of this time, orwhen the trolley harp has reached a point adjacent to the end of thetrolley the handle is removed from the bracket and the oven is removedfrom the article by the hoisting mechanism and returned along thesuspension track to the proximity of the spray booth |8. As the ovenrests above the platform 42 the air within the oven may be p'reheatedpreparatory to repeating the above cycle.

It will be understood that while in general, uniform` drying conditionswill be maintained in all of the ovens, the drying conditions in anyindividual oven may be manually or automatically varied if desired tomeet particular siccative requirements. V

In Figs. 8 and 9 I have illustrated still another method of handling myimproved drying ovens and an oven and platform specially adapted to thislast method.

In Fig. 8 I have illustrated a somewhat different type of industrialbuilding from that illustrated in Figs. la, 1b, and 5. In the buildingillustrated in Fig. 8 I have shown a floor 2'|| and a ceiling 225 buthave shown the central portion of this building extended upwardly toaccommodate a traveling crane generally indicated at 230. This cranecomprises a beam 232 supported at its ends by means of rollers 234 upontracks 235 which in turn are supported upon the sides of the building bybrackets 231. A hoist or lift device 238 is supported on the uppersurface of the beam 232 by rollers 240 and the operation of the crane iscontrolled from an operatorsvcage 242. A cable 250 extends downwardlyfrom the lifting device When the platform 84 carrying the wet coated.v

article |5 emerges from the spray booth I8 onto the rollers 200, thecrane is operated to impose an oven over the article. the platform by asuitable locking device such as that described in connection with theconstruction illustrated in Figs. 5, 6, and 7. The oven, platform, andarticle of manufacture may then be picked up by the crane and moved to alocation where drying or siccative action may be carried on. The dryinghood used is similar to that shown in Figs. 6 and 7 except thatelectrical harp |13 and bracket |80 are replaced by electrical outlets255 in Fig. 8 in the platform, and carriers |10, rollers |12, track |08and ceiling brackets |08 in Figs. 6 and 7 are replaced by floor rests260. The drying oven is also provided in the top thereof with a ringbolt 265 with which the hook 252 may be engaged to lift the oven.

On the floor of the portion of the building containing the crane 230, Ihave located a plurality of positions arranged to receive the ovens|40', platforms 94', and the articles I5 as units and equipped withelectrical outlets 210 to cooperate with the outlets 255. It is to thesepositions that crane 85 transfers the oven units from rollers 200, sothat the siccative action may occur, while the oven units are upon oorrests 280. It will be noted that one important distinction between theform of the invention illustrated in Figs. 1a, 1b, 2, and 3 and Figs. 5,6, and '1 and that illustrated The oven is latched to in Figs. 8 and 9is that in the first two forms the drying or siccative action takesplace while the ovens are in motion while in the last form the drying orsiccative action takes place while the ovens are stationary. l

In Fig. 10 I have illustrated still another modification of oven |40Figs. 6 and 7 or oven 20 Figs. 2 and 3. This oven is exactly similar indesign to either oven 20 or oven |40, except that either one end 300 orone side is hinged by a single hinge 302 at its uppermost edge or by aplurality of hinges disposed at different vertical levels, so as topermit of the removal of article i5 without the necessity of raising thehood from the'level at which the siccative action occurs. This type ofoven is of particular advantage in small installations such as repaintshops where it is not desirable to install extensive oven handlingequipment such as is illustrated in Figs. la and 1b, 5, and 8, and inwhich it is desired, at the same time to simulate factory conditions inthe drying or siccative action.

While I have illustrated and described certain specific mechanicalembodiments of the idea of my invention it is to be understood that theinvention is not limited thereto' but that such changes in the size,shape, and arrangement of parts may be resorted to as come within thescope of the subjoined claims.

Having now described my invention so that others skilled in the art towhich it appertains may fully understand the same, what I desire tosecure by Letters Patent is as follows:

l. In combination with a production line adapted to carry a train of wetcoated articles through a siccative process a plurality of portabledrying ovens comprising, open bottom hoods adapted to be applied to saidarticles individually without interrupting the progress of said train,means for applying said ovens to said articles at the beginning of saidsiccative process, means for removingr said ovens from said articles atthe end of said siccative process, means for returning said ovens fromthe end to the beginning of the siccative process portion of saidproduction line, and means for preheating the air contained in each ofsaid ovens immediately before said oven is applied to said article.

2. In combination with a production line adapted to carry a train of Wetcoated articles through a siccative process, a plurality of portabledrying ovens comprising, open bottom hoods adapted to be applied to saidarticles individually Without interrupting the progress of said train,means for applying said ovens to said articles at the beginning of saidsiccative process, means for removing said ovens from said articles atthe end of said siccative process, means for returning said ovens fromthe end to the beginning of the siccative process portion of saidproduction line, and means for conserving the heated air or gasescontained in each of the said ovens after the siccative process has beencompleted.

3. Apparatus for performing siccative action on articles of manufacturecomprising, a plurality of separate article supports movable along apredetermined path, a plurality of portable drying inclosurescooperating individually with said supports to provide separatecompartments for said articles during said siccative action, individualair heating and circulating means incorporated in each inclosure forcarrying on said siccative action, means for transporting said ovens andarticle supports, and means for supplying energy to said individual airheating and circulating means along the path over which said ovens andarticle supports are transported.

4. 'I'he method of performing siccative action on wet coated articles ofmanufacture which comprises, moving said articles in series along apredetermined path, enclosing each of said articles in succession,applying heat to each of said articles individually, moving said serieswhile the articles are so enclosed and heated, and finally, uncoveringeach of said articles in succession.

5. The method of performing siccative action on wet coated articles ofmanufacture which comprises, moving said articles in sequence along apredetermined path, applying separate ovens to said articlesconsecutively as said articles progress along said path, applying heatindividually to the interiors of said ovens as the ovens and includedarticles progress along said predetermined path and exposing saidarticles at the completion of said siccative action.

6. The method of performing siccative action on wet coated articles ofmanufacture which comprises, moving said articles in series along apredetermined path, applying a separate oven to each article insuccession Without interrupting the progress of said series, applyingheat to each oven While said oven and the included article are beingmoved as a unit along said predetermined path, and removing said ovensfrom said articles in succession as the siccative action on therespective articles is completed.

7. The method of performing siccative action on wet coated articles ofmanufacture which comprises, moving said articles in series along apredetermined path, enclosing said articles consecutively in separateovens, moving each article and enclosing oven as a unit along saidpredemined path, applying heat to each oven individually while it isbeing moved along said path, controlling the heat applied to each oventocarry on said siccative action in desired stages, and

removing said ovens from said articles at the completion of thesiccative action on the enclosed article. i

8. The method of performing siccative action on wet coated articles ofmanufacture which comprises, moving said articles in series to apredetermined point, enclosing each article separately in a portableoven, moving each oven and included article as a unit away from saidpredetermined point, applying heat interiorly only of each enclosingoven to carry on said siccative action, returning said ovens andincluded articles to a predetermined point, and finally removing eacharticle from the enclosing oven at said lastnamed predetermined point.

ROBERT R. LUNDY.

